NAME

SYNOPSIS

DESCRIPTION

Pass a long as parameter to control which version range of SSL/TLS versions to use.
The SSL and TLS versions have typically developed from the most insecure version to be
more and more secure in this order through history: SSL v2, SSLv3, TLS v1.0, TLS v1.1, TLS
v1.2 and the most recent TLS v1.3.
Use one of the available defines for this purpose. The available options are:
CURL_SSLVERSION_DEFAULT
The default acceptable version range. The minimum acceptable version is by
default TLS v1.0 since 7.39.0 (unless the TLS library has a stricter rule).
CURL_SSLVERSION_TLSv1
TLS v1.0 or later
CURL_SSLVERSION_SSLv2
SSL v2 (but not SSLv3)
CURL_SSLVERSION_SSLv3
SSL v3 (but not SSLv2)
CURL_SSLVERSION_TLSv1_0
TLS v1.0 or later (Added in 7.34.0)
CURL_SSLVERSION_TLSv1_1
TLS v1.1 or later (Added in 7.34.0)
CURL_SSLVERSION_TLSv1_2
TLS v1.2 or later (Added in 7.34.0)
CURL_SSLVERSION_TLSv1_3
TLS v1.3 or later (Added in 7.52.0)
The maximum TLS version can be set by using one of the CURL_SSLVERSION_MAX_ macros below.
It is also possible to OR one of the CURL_SSLVERSION_ macros with one of the
CURL_SSLVERSION_MAX_ macros. The MAX macros are not supported for WolfSSL.
CURL_SSLVERSION_MAX_DEFAULT
The flag defines the maximum supported TLS version by libcurl, or the
default value from the SSL library is used. libcurl will use a sensible
default maximum, which was TLS v1.2 up to before 7.61.0 and is TLS v1.3
since then - assuming the TLS library support it. (Added in 7.54.0)
CURL_SSLVERSION_MAX_TLSv1_0
The flag defines maximum supported TLS version as TLS v1.0. (Added in
7.54.0)
CURL_SSLVERSION_MAX_TLSv1_1
The flag defines maximum supported TLS version as TLS v1.1. (Added in
7.54.0)
CURL_SSLVERSION_MAX_TLSv1_2
The flag defines maximum supported TLS version as TLS v1.2. (Added in
7.54.0)
CURL_SSLVERSION_MAX_TLSv1_3
The flag defines maximum supported TLS version as TLS v1.3. (Added in
7.54.0)
In versions of curl prior to 7.54 the CURL_SSLVERSION_TLS options were documented to allow
only the specified TLS version, but behavior was inconsistent depending on the TLS
library.